The subject matter disclosed herein relates generally to superconducting magnet devices, and more particularly to systems and methods for cooling superconducting magnets, especially in Electrical Machines, Magnetic Storage and Magnetic Resonance Imaging (MRI) systems.
Superconducting coils, for example superconducting coils forming magnet device, are typically cryogenically cooled using a helium vessel. In these conventional magnet devices, the superconducting coils are cooled in a bath of liquid Helium (He), such that the coils are immersed in the liquid He. This cooling arrangement requires the use of an extremely large high pressure vessel that contains thousands of liters of liquid He. The resulting structure is not only expensive to manufacture, but heavy. In many situations reinforcement of the floor on which the magnet device is placed is needed, as well as the use of cranes to install the magnet device because typical elevators cannot support the weight of these magnet devices, such as MRI systems. Additionally, there are many areas (e.g., underserved or underdeveloped regions) where liquid helium delivery and service is not available. Accordingly, conventional magnet devices cannot be installed in these locations.
Additionally, the liquid He in these systems can sometimes boil-off, such as during a quench event, wherein the boiled-off helium escapes from the cryogen bath in which the magnet coils are immersed. Each quench, followed by a re-fill and re-ramp of the magnet, is an expensive and time consuming event. Additionally, in conventional superconducting magnet devices, an exterior venting system is needed to vent the gas, such as boiled-off helium, through venting pipes after magnet quenches. The venting pipes are difficult to install, and in some instances, impossible to install. Thus, added cost results, and in some situations, the venting of helium can have environmental or regulatory concerns.
Thus, conventional cooling arrangements for magnet devices can result in special installation requirements, the inability to install these systems in certain regions and a high cost to maintain.